The 299-page technical analysis (pdf) was prompted by the FCC’s June 20 deadline to respond to the ATT/T-Mobile merger. U.S. Cellular, the Rural Cellular Association, the Rural Telecommunications Group, MetroPCS and NTELOS also came out against AT&T’s buyout of T-Mobile in comments filed with the FCC yesterday.

AT&T responded:

“A company that has outsourced the management of its own network shouldn’t be giving advice to others,” an AT&T spokeswoman said, alluding to Sprint’s $5 billion outsourcing deal with Ericsson, which transferred the operations of its network to the Swedish infrastructure vendor.

“The opponents of the AT&T-T-Mobile merger have had their final say as part of the FCC’s formal pleading cycle and, not surprisingly, they have failed to offer any credible arguments to support their view that the Commission should deny the transaction. What is surprising, however, is their repeated head-in-the-sand insistence that no spectrum crisis exists.”

Separately, groups including Consumers Union and Media Access Project, a Washington-based non-profit law firm, in a news release said their filing would ask the FCC to deny the merger. The merger would harm competition and remove low-cost calling plans from the market, the groups said.

Sprint, in its filing, says AT&T could implement LTE, with double the spectrum efficiency, and use it on its unused “warehoused” spectrum in the 700 MHz, AWS and WCS bands.

The merger, announced March 20, would combine the second- and fourth-largest wireless carriers in the United States to create a new market leader, ahead of No. 1 Verizon Wireless. The FCC and Justice Department are in the midst of a review that AT&T executives have said will take about a year.